The following figure shows the data flow from the host computer to the printhead. Data sent from the host
computer is converted to image data and transmitted to the printhead through the gate array.
The following table lists the each function of the main components of the C186 MAIN board.
Table 2-7 Functions of the Main Board
IC
Location
Function
CPU
IC1
Receives data from the host computer and sends it to the input buffer
in RAM (under interrupt processing control). Extends the input data
held in the buffer to create image data. Loads this image data to the
image buffer in RAM.
Transfers the image data to the printhead
driver circuit.
Gate Array
IC2
Controls the functions below:
•
Controls output data from the internal block
•
Memory management
•
Address latch of the address/data bus from the CPU
•
Clock control unit
•
Bit manipulation
•
Interface control
•
Expanded parallel port
•
Printhead control
•
Motor control
EEPROM
IC 8
An electrically writable and erasable ROM used to hold information
such as the TOF position and bidirectional adjustment value.
ROM
IC 3
The ROM contains the program that runs the CPU and holds the
character design (also called the character generator).
RAM
IC 5
The RAM contains the CPU working area and the buffers
CG
IC 7
The CG contains the bitmap fonts for each character table
SLA7024M
IC 12
Driver circuit for the CR motor
TEA3718SDP
IC 11,14
Driver circuit for the PF motor
Hos t
Com put er
C P U
T M P9 6 C 0 4 1 AF
R A M
Gat e Array
E0 5B24 YA
Pr i nthe ad d r ive
cir cuite
Input
Buffer
Image
Buffer
Line Edit
Bu ff er
Print data
conversion 1
Print data
conversion 2
Data latch
and
data output
Im age data
transfer
Parallel I/F
Option I/F
Figure 2-31 Data Flow
LQ-2070 Service Manual
Operating Principles
Rev.A
2-23
Содержание 2070 - LQ B/W Dot-matrix Printer
Страница 1: ...EPSON TERMINAL PRINTER LQ 2070 SERVICE MANUAL EPSON 4006244 ...
Страница 5: ...REVISION SHEET Revision Issued Date Revision Page Rev A April 8 1996 1st issued ...
Страница 11: ...Product Description LQ 2070 Service Manual Figure 1 1 Exterior View of the LQ 2070 1 2 Rev A ...
Страница 55: ...LQ 2070 Service Manual Operating Principles Rev A 2 7 ...
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Страница 112: ...Disassembly and Assembly LQ 2070 Service Manual 3 34 Rev A ...
Страница 146: ...Maintenance LQ 2070 Service Manual 6 4 Rev A ...
Страница 165: ...EPSON ...